1. Field of the Invention
The subject invention relates generally to recreational vehicles and, more particularly, to an expandable or slidable room in a recreational vehicle that can be economically manufactured.
2. Description of Related Art
In order to increase the available interior space of recreational vehicles, such as trailers, including those commonly referred to as "fifth wheels," slide-out rooms can be made integral with the vehicle. During transit, these rooms can be retracted and stored in the vehicle's interior, with the exterior wall of the slide-out room approximately flush with the vehicle's exterior. To use the slide-out room, the vehicle is first parked and leveled. The slide-out room is then slid outward from the vehicle, increasing the interior space of the vehicle.
A problem with slide-out rooms is that during transit under adverse conditions such as rain, sleet, or snow, water tends to leak into the interior of the vehicle in the area between the slide-out room and the exterior wall of the vehicle. Water may even leak into the vehicle when the vehicle is being stored in inclement weather. The effectiveness of sealing systems currently being used can be improved to address this problem.
A number of motive devices are currently used to extend and retract slide-out rooms. These devices may be hydraulic, pneumatic, electric, simple gearing mechanisms, or various combinations thereof. An example of a prevalent electronically actuated gearing mechanism includes first and second cylindrical extending posts that are affixed to a power assembly. The power assembly is actuated electronically and is directly connected to the first cylindrical post using gears for extending and contracting an inner sleeve in the post. The second post is connected to the power assembly through a series of shafts and gear boxes. A gear box interposed between the posts has a hand crank adaptor so the posts can be extended or contracted by hand if the electrical power fails.
A disadvantage of this design exists in that the second post is connected to the power assembly through the series of gear boxes and shafts, and there may be synchronism problems between the first and second posts when they are extending or contracting. This can result in the room becoming skewed or binding during the transit sliding action. Another disadvantage of this design is that the post's inner sleeves are load-bearing, which can result in an excessive strain on the inner sleeves, posts, and power assembly when sliding the room. A further disadvantage of this design is that the inner sleeves of the posts are exposed to various environmental elements such as rain, dirt, and road grime when the room is extended, as well as during sliding of the room. These elements can slowly deteriorate the inner sleeves and the interior of the posts. An example of one type of slide-out mechanism is manufactured by Barker Manufacturing of Battle Creek, Mich.
Another slide-out mechanism design uses a pair of hydraulically-actuated cylindrical posts embodying some of the design features of the prior mechanism. This mechanism uses common hydraulic principles to extend and contract the room. A disadvantage of the hydraulically-actuated design is that the room is typically actuated from outside the vehicle, which can expose the user to adverse environmental elements. Other disadvantages of the hydraulic design include skewing and binding of the room while sliding the room, and load-bearing posts being exposed to environmental elements.
U.S. Pat. No. 2,822,212 discloses a mobile trailer that has a motor capable of driving three power screw members to expand and contract walls and floors of the mobile trailer.
U.S. Pat. No. 2,744,781 discloses an expansible vehicle body that has an expansion section on either side. An overlap of a floor member pivots downward when the vehicle body is in he expanded state. A hand crank is used to achieve expansion and retraction of the expansion sections.
Finally, housings having expansible sections and devices used to expand and contract expansible sections are disclosed in the following patents: U.S. Pat. Nos. 2,243,659; 2,519,517; 2,561,921; 2,739,833; 2,744,781; 2,822,212; and 3,341,986.